I recently have made the switch to mechanical pencils from old fashioned ones. I have to say I'm really enjoying them and my handwriting has improved (I used to write very hard and dark). I find that I really enjoy this particular kind: https://www.amazon.com/Paper-Mate-Sharpwriter-Mechanical-3030131/dp/B00006IEE4 because I like the "twist to advance" mechanism, which also makes the lead break far less easily. I figure since I spend a good 20-30 hours a week writing on paper, I should just invest in a high-quality refillable mechanical pencil (I am aware its possible to refill the sharpwriters). I want one that is similar in design to the above ones, with a head that you twist to advance or retract the lead. Any recommendations? I probably don't want to spend more than $20 on a pencil.